Ans. (a) Early repolarization variant.There is sinus rhythm at 60 beats/min, normal axis and intervals, and no evidence of chamber enlargement. There is ST-segment elevation most prominent in the precordial leads V4 through V6 with a "notched" J-point. The differential diagnosis of ST-segment elevation includes ischemia, ventricular aneurysm, pericarditis, electrolyte abnormalities, and repolarization abnormalities. The morphology of the ST segment here is consistent with an "early-repolarization" pattern that is common and overall normal in young, otherwise healthy people. There are some reports suggesting a small increase in sudden cardiac death risk, particularly if the J-point is above the baseline by more than 1 mm in the inferior leads, but this association merits further study. No further workup is required; this is an overall normal EGG.ST-segment elevation with a notched J point (arrow) consistent with an early repolarization pattern.